Boron possesses a high intrinsic energy density; however, its practical utilization is hindered by ignition delays and incomplete combustion caused by the diffusion-limiting B₂O₃ surface layer. To overcome this barrier, boron particles were functionalized with nanoscale nitrosonium tetrafluoroborate (NOBF₄) to produce a reactive composite particle system. Thermogravimetric analysis, shock-tube ignition measurements, and bomb-calorimetric tests were conducted to evaluate the gas–particle combustion characteristics of the coated particles. Upon heating, NOBF₄ thermally decomposes and releases fluorine-containing species that chemically etch and fluidize the surface oxide layer, thereby enhancing oxygen transport across the gas–particle interface. As a result, the coated particles exhibit a substantially reduced ignition delay and an increased heat release compared to uncoated boron. These findings demonstrate that NOBF₄ acts as an effective interfacial modifier that enhances the oxidation reactivity of boron particles, highlighting its potential for high-energy combustion and propulsion applications.